So, what’s the point on adding an external crossover if I won’t be able to change the crossover point at the end of the chain. I guess external crossovers are for speakers without internal crossovers. Am I missing something?
A bi-amp or tri-amp systems are a big-boy playground. There are a number of reasons to use a proper crossover even on a loudspeaker that has an internal crossover. Most have already been discussed. A proper crossover will give you flexibility that a mere volume control can't do. You can affect the built-in crossover to some limited extent and you can simply bypass the internal crossover for full control. Running both amps full range is eliminating one of the reasons to bi-amp in the first place. There is a difference between being ABLE to do something and doing something the right way. If you are going to all that effort to bi-amp you should want to get the maximum out of that configuration.
OK, I said my piece.